Rolled condenser for sparking apparatus



F. KRATZ.

ROLLED CONDENSER FOR SPARKlNG APPARATUS. v

APPLICATION FILED AUG.20, 1919.

1 ,328,925 Patented Jan. 27, 1920.

I Bh/ATFURN Ex/s M i m, figM;

UNITED STATES PATENT OFFICE FRANZ KBATZ, OF STUTTGART, GERMANY, ASSIGNOR TO THE FIRM 01 ROBERT BOSCH AKTIENGESELLSCHAFT, OF STUT'IGART, GERMANY.

ROLLED CONDENSER FOR SPARKING APPARATUS.

Specification of Letters Patent.

Patented Jan. 2'7, 1920.

Application filed August 20, 1919. Serial No. 318,807.

To all whom it may concern:

Be it known that I, FRANZ KnA'rz, engineer, a citizen of Germany, residing at and whose post oflice address is Stuttgart, Schlosstrasse 59, Germany, have invented certain new and useful Improvements in Rolled Condensers for Sparking Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the in vention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to condensers for sparkin apparatus which are made up of strips '0 paper and tinfoil rolled together in the known manner. The salient features of the new condenser consist in two metal disks placed opposite to each other and having short pipes protruding inward from their centers upon which the strips of paper and tinfoil are wound. In order to obtain a good contact between the metal disks and the two tinfoil strips these latter are made somewhat wider than the distance between the disks so that when the winding operation is performed the one edge of each strip abuts against a disk and is thus caused to curl up and press firmly against it. By the pull exerted on the stri s during winding the disks are prevented rom moving apart so that no rivets, screws, soldering, spring pressure, or any other special means are required to keep the frame together.

The invention is illustrated in the drawing in which Figure 1 represents a section through a condenser viewed from the side, and Fig. 2 shows the tinfoil and paper strips as they appear while being wound onto the condenser frame or spool.

Two metal disks or cheeks b with protruding ring portions or short pipes a are arranged in parallel planes so that the rings a are situated opposite to each other and a certain distance apart. The space between the disks 6 may be bridged by a layer of insulating material 0 supported by the rings a, and upon the reel or spool thus formed the paper and tinfoil strips d e are wound. The tinfoil strip 6 is made somewhat broader than the distance between the disks 1) so that it is caused to curl up at one edge during winding and is thus pressed firmly against its disk and establishes an intimate contact with the same. By the pressure applied by the tightly wound strips the disks that serve as mountings are prevented from being shifted outward from the middle. This may also be prevented by gluing the rings a to the insulation 0.

The advantage of the new method of construction over all known forms is that metal mountings are employed which keep the condenser together without the aid of any special fixing means such as rivets, solder, springs, screws or the like.

I claim 1. A condenser comprising two cheeks with middle protuberances opposite to but apart from each other, and paper and-tinfoil strips wound tightly onto the said protuberances so as to prevent the cheeks from separating.

2. A condenser comprising two disks with middle annular protuberances opposite to but apart from each other, and paper and tinfoil strips wound tightly onto the said I rotuberances so as to prevent the disks rom separating.

In testimony whereof I afiix my signature, in presence of two witnesses.

FRANZ KRATZ.

Witnesses:

Anonr LEHHERZ, HERMANN SCHNEIDER. 

